title: Distribution patterns of infection with multiple types of human papillomaviruses and their association with risk factors.
abstract: BACKGROUND
  Infection with multiple types of human papillomavirus (HPV) is one of the main risk factors associated with the development of cervical lesions. In this study, cervical samples collected from 1,810 women with diverse sociocultural backgrounds, who attended to their cervical screening program in different geographical regions of Colombia, were examined for the presence of cervical lesions and HPV by Papanicolau testing and DNA PCR detection, respectively.
  
  
  RESULTS
  The negative binomial distribution model used in this study showed differences between the observed and expected values within some risk factor categories analyzed. Particularly in the case of single infection and coinfection with more than 4 HPV types, observed frequencies were smaller than expected, while the number of women infected with 2 to 4 viral types were higher than expected. Data analysis according to a negative binomial regression showed an increase in the risk of acquiring more HPV types in women who were of indigenous ethnicity (+37.8%), while this risk decreased in women who had given birth more than 4 times (-31.1%), or were of mestizo (-24.6%) or black (-40.9%) ethnicity.
  
  
  CONCLUSIONS
  According to a theoretical probability distribution, the observed number of women having either a single infection or more than 4 viral types was smaller than expected, while for those infected with 2-4 HPV types it was larger than expected. Taking into account that this study showed a higher HPV coinfection rate in the indigenous ethnicity, the role of underlying factors should be assessed in detail in future studies.
authors.affiliation: Molecular Biology Department, Fundacion Instituto de Inmunologia de Colombia, Bogota, Cundinamarca, Colombia.
authors.forename: Sara
authors.initials: S
authors.lastname: Soto-De Leon
authors.forename: Milena
authors.initials: M
authors.lastname: Camargo
authors.forename: Ricardo
authors.initials: R
authors.lastname: Sanchez
authors.forename: Marina
authors.initials: M
authors.lastname: Munoz
authors.forename: Antonio
authors.initials: A
authors.lastname: Perez-Prados
authors.forename: Antonio
authors.initials: A
authors.lastname: Purroy
authors.forename: Manuel Elkin
authors.initials: ME
authors.lastname: Patarroyo
authors.forename: Manuel Alfonso
authors.initials: MA
authors.lastname: Patarroyo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D052685:Alphapapillomavirus / Q000235:genetics / Q000302:isolation & purification*; D003105:Colombia / Q000453:epidemiology; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D005820:Genetic Testing; D005843:Geography; D006801:Humans; D008875:Middle Aged; D030361:Papillomavirus Infections / Q000150:complications / Q000453:epidemiology* / Q000235:genetics / Q000821:virology*; D012307:Risk Factors; D013020:South America / Q000453:epidemiology; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000821:virology*; D055815:Young Adult; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000821:virology*
chemical_list: D004279:DNA, Viral